The present invention relates to a light transmitting electromagnetic wave-shielding material for shielding an electromagnetic wave and through which the inside of a microwave oven, a measuring instrument, or the like or a screen of a CRT, plasma display panel, or the like can be seen, and relates to a method of manufacturing the same.
As disclosed in Japanese Patent No. 2,717,734, a conventional light-transmitting electromagnetic wave-shielding material includes a hydrophilic transparent resin layer 32 laminated on a transparent substrate 3 An electroless plating layer 334 is laminated on the hydrophilic transparent resin layer 32 in a pattern, and a black pattern section 36 is formed in the hydrophilic transparent resin layer 32 under the electroless plating layer (see FIG. 1). The electroless plating layer microscopically looks like a black pattern in a fine mesh or the like to an observer.. However, the aforementioned light-transmitting electromagnetic wave-shielding material has issues described below.
In particular although a bottom surface of the electroless plating layer has a black color, a top surface of the clectroless plating layer maintains a metallic luster. Therefore, when the light-transmitting electromagnetic wave-shielding material is attached to the front of a display (for example, when a shielding filter is set at the front of the display and a grounding section is provided on a front surface of the filter (observer side) or a rear surface of the filter (display side) to ensure an electrical connection (grounding) between a display case and the filter), the surface having a black color faces the observer and the surface having the metallic luster faces the display. In this case, there is a disadvantage in that visibility of the display images observed by the observer are deteriorated since the light radiated from the display is reflected from the surface of the electroless plating layer having the metallic luster and illuminates the display screen again.
To remove this disadvantage (that is, to improve visibility by suppressing reflection from a metallic surface) the following methods are available:
(1) A method of roughening a surface by sand blasting or the like to form surface irregularities;
(2) A method of forming a black coating by oxidation;
(3) A method of coating an irregular film by printing or the like; and
(4) A method of coating a black film by printing or the like.
However, since the hydrophilic transparent resin layer and the electroless plating layer are subjected to a physical impact or chemical change in any of the above methods (1) to (4), transparency of the hydrophilic transparent resin layer is deteriorated, and an electromagnetic wave-shielding effect is impaired due to damage to the electroless plating layer. Another issue is that reduced conductivity of the electroless plating layer makes grounding difficult.
In addition, in methods (1), (3), and (4), it is extremely difficult to roughen a side surface 39 of the electroless plating layer or coat an irregular film or the like thereon. Therefore, light reflection from the side surface 39 of the electroless plating layer cannot be suppressed, so that visibility at slant angles, in particular, cannot be improved.
In methods (3) and (4), in particular, it is difficult to coat an irregular (projections-and-depressions) film or a black film only on a portion on which the electroless plating layer exists (so-called patterning). Furthermore, in this case, a resist process or the like is required for grounding so that an irregular film is formed except for a portion of the electroless plating layer to be grounded. Consequently, productivity is decreased.
Accordingly, an object of the present invention is to provide a light-transmitting electromagnetic wave-shielding material which has favorable properties such as transparency, electromagnetic wave-shielding effect, visibility, and the like, and which is easy to be grounded, and a method of manufacturing the same.
In order to achieve the above object, the present invention has the following constitutions.
According to a first aspect of the present invention, there is provided a light-transmitting electromagnetic wave-shielding material, wherein a hydrophilic transparent resin layer is laminated on a transparent substrate. An electroless plating layer is laminated on the hydrophilic transparent resin layer in a pattern. A black pattern section is formed only in a portion of the hydrophilic transparent resin layer under the electroless plating layer, and a black electroplating layer covering the electroless plating layer is laminated.
According to a second aspect of the present invention, there is provided a light-transmitting electromagnetic wave-shielding material, wherein a hydrophilic transparent resin layer is laminated on a transparent substrate. An electroless plating layer is laminated on the hydrophilic transparent resin layer in a pattern. A black pattern section is formed only in a portion of the hydrophilic transparent resin layer under the electroless plating layer. An electroplating layer is laminated on the electroless plating layer, and a black electroplating layer covering the electroless plating layer and the electroplating layer is laminated.
According to a third aspect of the present invention, there is provided the light-transmitting electromagnetic wave-shielding material according to the first aspect, wherein the black electroplating layer covers a top surface of the electroless plating layer exposed on an opposite side of a surface on which the black pattern section is formed, as well as a side surface of the electroless plating layer.
According to a fourth aspect of the present invention, there is provided the light-transmitting electromagnetic wave-shielding material according to the second aspect, wherein the black electroplating layer covers a top surface of the electroplating layer exposed on an opposite side of a surface on which the electroless plating layer is formed, as well as respective side surfaces of the electroless plating layer and the electroplating layer.
According to a fifth aspect of the present invention, there is provided the light-transmitting electromagnetic wave-shielding material according to the first aspect, wherein the black electroplating layer covers only a top surface of the electroless plating layer exposed on an opposite side of a surface on which the black pattern section s formed.
According to a sixth aspect of the present invention, there is provided the light-transmitting electromagnetic wave-shielding material according to the second aspect, wherein the black electroplating layer covers only a top surface of the electroplating layer exposed on an opposite side of a surface on which the electroless plating layer is formed.
According to a seventh aspect of the present invention, there is provided the light-transmitting electromagnetic wave-shielding material according to any one of the first to sixth aspects, wherein the black electroplating layer is nickel, chromium, tin, rhodium, or ruthenium metal or an alloy of any of these.
According to an eighth aspect of the present invention, there is provided a method of manufacturing a light-transmitting electromagnetic wave-shielding material comprising forming a hydrophilic transparent resin layer on a transparent substrate. An electroless plating layer is formed on the hydrophilic transparent resin layer so that the hydrophilic transparent resin layer is blackened when seen from its rear side. A resist section is formed in a desired pattern on the electroless plating layer. Etching is performed to remove a non-resist section of the electroless plating layer, on which the resist section is not formed, while patterning in black the hydrophilic transparent resin layer under the electroless plating layer when seen from its rear side. The resist section on the electroless plating layer is removed from the electroless plating layer, and a black electroplating layer is formed to cover the electroless plating layer.
According to a ninth aspect of the present invention, there is provided a method of manufacturing a light-transmitting electromagnetic wave-shielding material comprising forming a hydrophilic transparent resin layer on a transparent substrate. An electroless plating layer is formed on the hydrophilic transparent resin layer so that the hydrophilic transparent resin layer is blackened when seen from its rear side. An electroplating layer is formed on the electroless plating layer a resist section is formed in a desired pattern on the electroless plating layer. Etching is performed to remove the electroless electroplating layer on a non-resist section, where the resist section is not formed, of the electroplating layer, while patterning in black the hydrophilic transparent resin layer under the electroless plating layer when seen from its rear side. The resist section on the electroless plating layer is removed from the electroless plating layer, and a black electroplating layer covering the electroplating layer and the electroless plating layer is formed.
According to a 10th aspect of the present invention, there is provided a method of manufacturing a light-transmitting electromagnetic wave-shielding material comprising forming a hydrophilic transparent resin layer on a transparent substrate. An electroless plating layer is formed on the hydrophilic transparent resin layer so that the hydrophilic transparent resin layer is blackened when seen from its rear side, and a resist section is formed in a desired pattern on the electroless plating layer. Etching is performed to remove a non-resist section the electroless plating layer, on which the resist section is not formed, while patterning in black the hydrophilic transparent resin layer under the electroless plating layer when seen from its rear side. The resist section on the electroless plating layer from the electroless plating layer, forming an electroplating layer on the electroless plating layer, and a black electroplating layer covering the electroplating layer and the electroless plating layer is formed.
According to an 11th aspect of the present invention, there is provided a method of manufacturing a light-transmitting electromagnetic wave-shielding material comprising forming a hydrophilic transparent resin layer on an entire surface of a transparent substrate. An electroless plating layer is formed on an entire surface of the hydrophilic transparent resin layer so that the hydrophilic transparent resin layer is blackened when seen from its rear side, and a resist section is formed in a desired pattern on the electroless plating layer. An electroplating layer is formed on a non-resist section of the electroless plating layer, on which the resist section is not formed, and the resist section on the electroless plating layer from the electroless plating layer. Etching is performed to remove an electroplating layer non-existent portion of the electroless plating layer while patterning in black the hydrophilic transparent resin layer under the electroless plating layer when seen from its rear side; and a black electroplating layer covering the electroplating layer and the electroless plating layer is formed.
According to a 12th aspect of the present invention, there is provided a method of manufacturing a light-transmitting electromagnetic wave-shielding material comprising forming a hydrophilic transparent resin layer on a transparent substrate. An electroless plating layer is formed on the hydrophilic transparent resin layer so that the hydrophilic transparent resin layer is blackened when seen from its rear side. A black electroplating layer is formed on the electroless plating layer, and a resist section is formed in a desired pattern on the black electroplating layer. Etching is performed to remove a non-resist section of the black electroplating layer, on which the resist section is not formed, while patterning in black the hydrophilic transparent resin layer under the electroless plating layer when seen from its rear side, and then the resist section on the black electroplating layer is removed from the black electroplating layer.
According to a 13th aspect of the present invention, there is provided a method of manufacturing a light-transmitting electromagnetic wave-shielding material comprising forming a hydrophilic transparent resin layer on a transparent substrate. An electroless plating layer is formed on the hydrophilic transparent resin layer so that the hydrophilic transparent resin layer is blackened when seen from its rear side, an electroplating layer is formed on the electroless plating layer, a black electroplating layer is formed on the electroless plating layer, and a resist section is formed in a desired pattern on the black electroplating layer. Etching is performed to remove a non-resist section of the black electroplating layer, on which the resist section is not formed, while patterning in black the hydrophilic transparent resin layer under the electroless plating layer when seen from its rear side, and then the resist section on the black electroplating layer is removed from the black electroplating layer.
According to a 14th aspect of the present invention, there is provided a method of manufacturing a light-transmitting electromagnetic wave-shielding material, wherein the black electroplating layer in any one of the eighth to 13th aspects is nickel, chromium, tin, rhodium, ruthenium metal, or an alloy of any of these.
According 15th aspect of the present invention, there is provided a light-transmitting electromagnetic wave-shielding material manufactured by the method of manufacturing the light-transmitting electromagnetic wave-shielding material according to any one of the eighth to 14th aspects.